In general, mobile communication systems have been developed for the purpose of providing communication while securing user mobility. The mobile communication systems have reached a stage where a high speed data communication service can be provided as well as voice communication on the strength of the rapid development of technology. Currently, a standardization operation from a 3rd Generation Partnership Project (3GPP) system to a Long Term Evolution (LTE)/LTE-Advanced (LTE-A) system is being progressed as one of the next generation mobile communication systems. LTE is a technology which implements high speed packet-based communication having a transmission rate of 100 Mbps. As types of services using wireless mobile communication systems significantly diversify, a demand for a new technology for more efficiently supporting newly appearing services increases, and accordingly, new methods and technologies are being researched for the LTE/LTE-A systems.
Device to Device (D2D) communication is a technology recently researched and enables a User Equipment (UE) to basically perform direct communication with another UE located adjacently to the UE.
Through the D2D communication technology, the UE may perform discovery (hereinafter, referred to as “D2D-D”) in which the UE looks for UEs located adjacently to the UE itself and can perform direct communication (hereinafter, referred to as “D2D-C”) with a UE requiring communication. Through the use of the D2D communication, it is possible to efficiently use radio resources in comparison with communication through a base station using the conventional wireless network. Further, through the use of the D2D communication, the UE can directly provide information to a UE which needs the information by using a method of discovering neighboring UEs, so that Social Networking Services (SNS) and advertisement services can be more efficiently supported.